The largest tokamak in the world located in Culham, England and is the only operational fusion experiment that is capable of producing fusion energy. It involves a partnership of several European nations and has been investigating the potential for thermonuclear power by nuclear fusion.

(p. 204) The origins of JET extend back to 1970 when the Council of the European Community provided the legal framework for the development of a European fusion device. After construction of the experimental nuclear reactor, which began in 1977, the first JET plasma was achieved in 1983. In 1997, 16 MW of fusion energy was produced for a total power input of 24 MW. The European Fusion Development Agreement (EFDA) was established in 1999 and has responsibility for the future use of JET and defines JET’s scientific programme, allowing for the detailed study of nuclear fusion by many scientists and engineers from all over Europe. While JET is effectively a scientific experiment, ITER is a reactor-scale experiment designed to deliver ten times the amount of power that it consumes. DEMO is expected to be the first fusion nuclear power plant to provide electricity to the national power grid.

http://www.aiche.org/ Official website of EFDA JET programme.